This disclosure relates generally to connectorization of optical fibers in fiber optic connectors, and more particularly to forming a fiber bulge in an end of an optical fiber to position the optical fiber in a ferrule bore of a ferrule assembly to improve insertion loss.
Optical fibers are useful in a wide variety of applications, including the telecommunications industry for voice, video, and data transmissions. In a telecommunications system that uses optical fibers, there are typically many locations where fiber optic cables that carry the optical fibers connect to equipment or other fiber optic cables. To conveniently provide these connections, fiber optic connectors are often provided on the ends of fiber optic cables. The process of terminating individual optical fibers from a fiber optic cable is referred to as “connectorization.” Connectorization can be done in a factory, resulting in a “pre-connectorized” or “pre-terminated” fiber optic cable, or the field (e.g., using a “field-installable” fiber optic connector).
Regardless of where installation occurs, a fiber optic connector typically includes a ferrule with one or more bores that receive one or more optical fibers. The ferrule supports and positions the optical fiber(s) with respect to a housing of the fiber optic connector. Thus, when the housing of the fiber optic connector is mated with another connector (e.g., in an adapter), an optical fiber in the ferrule is positioned in a known, fixed location relative to the housing. This allows an optical connection to be established when the optical fiber is aligned with another optical fiber provided in the mating connector.
Each bore of the ferrule in a fiber optic connector typically extends to a front end face of the ferrule. With such a design, an optical fiber can be inserted into the ferrule bore of the ferrule such that an end of the optical fiber is extended beyond the ferrule end face. As an example, after securing the optical fiber relative to the ferrule (e.g., by using a bonding agent in the bore), an optical surface may be formed on the end of the optical fiber at the front of the ferrule to form a terminal end of the optical fiber. Forming the optical surface may include cleaving the excessive optical fiber protruding from the ferrule end face. To reduce or eliminate scratches, cracks, or other blemishes on the cleaved end portion of the optical fiber that could otherwise cause optical attenuation, the cleaved end portion of the optical fiber can be polished to an end face to form an optical surface. At this optical surface, sometimes the position of the core of the optical fiber may not be within industry specifications, which can negatively impact optical communication by causing insertion loss. For example, the centration of the optical fiber depends on ferrule bore and optical fiber diameters and how the optical fiber is secured to the ferrule bore. Depending on the contact line of the fiber inside the ferrule bore, the optical axis of the optical fiber is offset with respect to the ferrule bore axis. This can cause significant lateral misalignment losses.